To me every generic question like this post, the first response should be an AI response, followed by individuals personal take and experience.OP:Start small and Make Your Big Mistakes Early. 

Since they can't do each property individually, they use comparable sales to make broad generalizations to determine percent changes.

Like I said before - if I, as an individual investor, can make the fee payment at once, how can RADD, as an entity with that type of professed liquidity, not refund the exact same amount - not more, not less - at once?

Residences and cars are not purchased in individuals names.  

I have used LLCs individually for the properties that I've owned and I'm glad I did. 

What i would recommend is joining a REA or other real estate meet-up group where you can connect with other likeminded individuals consistently and share knowledge.

If you are receiving 3-5 per week that’s not bad, considering the price is what most individuals look for when looking to rent.

How much time / cash / other are each individual expected to contribute?

Networking events, seminars, and workshops help you connect with like-minded individuals and mentors.

Some other other options to consider that may be easier, would be these: 1) Take your $840k and have a money manager at Vanguard, Fidelity or Schwab invest it in individual bonds at a 4-5% return.